Re: regression in 2.6.27.45 with usb and suspend-to-disk

[Corey Wright <undefined@pobox.com>]

On Wed, 3 Feb 2010 15:31:49 -0500 (EST)
Alan Stern <stern@rowland.harvard.edu> wrote:

> On Wed, 3 Feb 2010, Corey Wright wrote:
> 
> > the device is a usb SD reader w/ SD card in it.
> > 
> > # cat /sys/bus/usb/devices/1-8/product
> > USB 2.0  SD MMC READER 
> > 
> > i removed the media reader after the failed suspend (it is only used at
> > boot-up to hold the LUKS key material to decrypt the filesystem) but the
> > message is the same:
> > 
> > [ 4002.585329] ehci_hcd 0000:00:10.4: suspend root hub
> > [ 4002.585334] ehci_hcd 0000:00:10.4: suspend failed because port 8 is
> > resuming
> > [ 4002.585338] usb usb1: bus suspend fail, err -16
> > 
> > and /sys/bus/usb/devices/1-8 no longer exists (little
> > alone /sys/bus/usb/devices/1-8/power/wakeup):
> > 
> > # ls -1 /sys/bus/usb/devices/
> > 1-0:1.0
> > 1-7
> > 1-7:1.0
> > 2-0:1.0
> > 2-1
> > 2-1:1.0
> > 3-0:1.0
> > 4-0:1.0
> > 5-0:1.0
> > usb1
> > usb2
> > usb3
> > usb4
> > usb5
> > 
> > > And what happens if you do:
> > > 
> > > 	echo disabled >/sys/bus/usb/devices/1-8/power/wakeup
> > > 
> > > before trying to hibernate?
> > 
> > it's the same immediately after a reboot (and before suspending), a
> > successful suspend, or a failed suspend:
> > 
> > # echo disabled >/sys/bus/usb/devices/1-8/power/wakeup 
> > bash: echo: write error: Invalid argument
> > 
> > and as previously said, that sysfs entry does not exist if the media
> > reader is removed, though the error appears to continue to refer to that
> > port/device.
> 
> Okay, thanks for testing.  That narrows it down, and I believe the 
> patch below will fix the bug.  Let me know how it works.

after applying the patch the system suspended successfully three times in a
row (before i got tired of watching it resume, which takes minutes due to
bios hardware initialization).

i looked in dmesg after a suspend and all the usb debug messages looked
innocuous.

the patch appears to have fixed the problem.  i need to rebuild the
netbook's kernel with the new patch and see if that fixes it, too.  if it
doesn't fix the netboot suspending, then i'll follow-up.

thanks for your time debugging the problem and for the patch!

corey
-- 
undefined@pobox.com